Ion pump-interacting proteins: promising new partners.

The sorting and regulation of the Na,K and H,K-ATPases requires that the pump proteins must associate, at least transiently, with kinases, phosphatases, scaffolding molecules, and components of the cellular trafficking machinery. The identities of these interacting proteins and the nature of their associations with the pump polypeptides have yet to be elucidated. We have begun a series of yeast two-hybrid screens employing structurally defined segments of pump polypeptides as baits in order to gain insight into the nature and function of these interacting proteins.